random n.随机 a.随机的
seldom adv.很少；不常
serfdom n. 农奴的身分; 农奴制度
thralldom n. 奴隶的'身分,束缚
wisdom n.(古人的)名言，格言
例句：
Where people were concerned, his threshold of boredom was low.
涉及人的事情，他便极易感到厌烦。
We played cards to relieve the boredom of the long wait.
长时间等待实在无聊，我们就打扑克来解闷儿。
One cannot choose freedom for oneself without choosing it for others.
人不能光为了自己的自由而不顾别人的自由。
Basic human rights, including freedom of speech, are now guaranteed.
现在，包括言论自由在内的基本人权已有了保障。